I think there are tutorials on heating the unit up in an oven to get it to re-stick...but that sounds pretty preposterous. I think some people have replaced the ribbon with soldered wires.... In either case, it sounds really difficult and iffy.
I've always been really careful to not touch the two adjustments on top. Of course, one day I came home from work to find my kid and a friend playing with it, and the friend was pulling on BOTH adjustments every time it was his turn! Dang, son! New rule in house...don't touch Virtual Boy without permission. And don't touch the knobs.